The goal of this research is to improve the safety of patients who suffer aneurysmal subarachnoid hemorrhage (aSAH) by improving their access to recommended transcranial Doppler (TCD) monitoring for cerebral vasospasm, a complication that affects 30-70% of aSAH patients and leads to death in nearly half. Other diagnostic modalities are impractical for serial monitoring due to expense, radiation exposure and logistics whereas TCD can be performed at the patient?s bedside. TCD is recommended by 5 professional societies for monitoring cerebral vasospasm yet is grossly underused nationally. The problem we address is the scarcity of trained providers: there just 82 laboratories accreditated by the Intersocietal Accreditation Commission (IAC) Vascular Testing to perform TCD. We propose a TCD simulator that can be applied for both training and competency testing. Our rationale is that training more providers and helping them to maintain skill will improve patient access to this recommended diagnostic procedure; studies show that ultrasound simulators can meet these needs. To develop the proposed simulator, we will leverage a prototype TCD simulator that we are currently developing (MH115883) and test its performance. Aim #1: We will complete the development of a simulator for training and skill assessment in performing TCD examination for cerebral vasospasm. A Case Library will be created with 24 cases reflecting a range of disease severity, each prepared from actual patient data. We will verify the accuracy of the simulation by comparing the blood flow velocity measured from the simulator waveforms with the true velocities in the 3D models. We will verify the simulator?s clinical realism by comparing spectral Doppler waveforms captured on the simulator with patient waveforms recorded by expert sonologists. Aim #2: We will create a curriculum for teaching TCD examination for cerebral vasospasm and implement metrics of skill based on systematic insonation and the velocities measured. We will assess the efficacy of the curriculum and the validity of the skill metrics. Aim #3: We will verify the clinical validity of the simulator by randomizing trainees to simulator- based vs. standard training and comparing the post-training skill in performing TCD examination for cerebral vasospasm. HEALTH CARE BENEFIT: The proposed research will improve patient safety by improved, evidence-based utilization of TCD to diagnose cerebral vasospasm, eventually reducing morbidity and mortality.